<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
 <head>
  <meta http-equiv="content-type" content="text/html; charset=UTF-8">
  <title>Pings a server connection, or tries to reconnect if the connection has gone down</title>
 </head>
 <body class="docs"><div id="layout">
  <div id="layout-content"><div id="function.maxdb-ping" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">maxdb_ping</h1>
  <h1 class="refname">maxdb::ping</h1>
  <p class="verinfo">(PECL maxdb &gt;= 1.0)</p><p class="refpurpose"><span class="refname">maxdb_ping</span> -- <span class="refname">maxdb::ping</span> &mdash; <span class="dc-title">Pings a server connection, or tries to reconnect if the connection has gone down</span></p>

 </div>

 <div class="refsect1 description" id="refsect1-function.maxdb-ping-description">
  <h3 class="title">说明</h3>
  <p class="para">过程化风格</p>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>maxdb_ping</strong></span>
    ( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$link</code></span>
   ) : <span class="type">bool</span></div>

  <p class="para rdfs-comment">面向对象风格</p>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>maxdb::ping</strong></span>
    ( <span class="methodparam">void</span>
   ) : <span class="type">bool</span></div>

  <p class="para rdfs-comment">
   Checks whether the connection to the server is working. If it has gone
   down, and global option <em>maxdb.reconnect</em> is enabled
   an automatic reconnection is attempted.
  </p>
  <p class="para">
   This function can be used by clients that remain idle for a long while,
   to check whether the server has closed the connection and reconnect if
   necessary.
  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.maxdb-ping-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   成功时返回 <strong><code>TRUE</code></strong>， 或者在失败时返回 <strong><code>FALSE</code></strong>。
  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-function.maxdb-ping-examples">
  <h3 class="title">范例</h3>
  <div class="example" id="example-1387">
   <p><strong>Example #1 面向对象风格</strong></p>
   <div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$maxdb&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">maxdb</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"MONA"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"RED"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"DEMODB"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;check&nbsp;connection&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">maxdb_connect_errno</span><span style="color: #007700">())&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Connect&nbsp;failed:&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">maxdb_connect_error</span><span style="color: #007700">());<br />&nbsp;&nbsp;&nbsp;exit();<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;check&nbsp;if&nbsp;server&nbsp;is&nbsp;alive&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">$maxdb</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">ping</span><span style="color: #007700">())&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf&nbsp;</span><span style="color: #007700">(</span><span style="color: #DD0000">"Our&nbsp;connection&nbsp;is&nbsp;ok!\n"</span><span style="color: #007700">);<br />}&nbsp;else&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf&nbsp;</span><span style="color: #007700">(</span><span style="color: #DD0000">"Error:&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$maxdb</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">error</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;close&nbsp;connection&nbsp;*/<br /></span><span style="color: #0000BB">$maxdb</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">close</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
   </div>

  </div>
  <div class="example" id="example-1388">
   <p><strong>Example #2 过程化风格</strong></p>
   <div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$link&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">maxdb_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"MONA"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"RED"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"DEMODB"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;check&nbsp;connection&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">maxdb_connect_errno</span><span style="color: #007700">())&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Connect&nbsp;failed:&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">maxdb_connect_error</span><span style="color: #007700">());<br />&nbsp;&nbsp;&nbsp;exit();<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;check&nbsp;if&nbsp;server&nbsp;is&nbsp;alive&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">maxdb_ping</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf&nbsp;</span><span style="color: #007700">(</span><span style="color: #DD0000">"Our&nbsp;connection&nbsp;is&nbsp;ok!\n"</span><span style="color: #007700">);<br />}&nbsp;else&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf&nbsp;</span><span style="color: #007700">(</span><span style="color: #DD0000">"Error:&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">maxdb_error</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">));<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;close&nbsp;connection&nbsp;*/<br /></span><span style="color: #0000BB">maxdb_close</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
   </div>

  </div>
  <p class="para">以上例程的输出类似于：</p>
  <div class="example-contents screen">
<div class="cdata"><pre>
Our connection is ok!
</pre></div>
  </div>
 </div>


</div></div></div></body></html>